Read More

Lonergan spent a season with Leeds in 2011/12 and rejoined the club last year, signing a two year deal. However, both parties agreed to part company with 12 months left to run on that contract.

Speaking to the Leeds website, Lonergan said: “I really enjoyed being back at Leeds United again and I’d like to thank all of the staff and players I’ve worked with every day. The biggest thank you must go to the supporters though and I wish the club the best of luck for next season.”

Andy Lonergan

The keeper has spent the majority of his career with hometown club Preston North End, making more that 200 appearances.

He then joined Leeds before moving onto Bolton, Fulham and Wolves. He was tipped for a move to Arsenal in 2005 but suffered the first of two cruciate knee ligament injuries while training for Preston.

Lonergan joins Paddy McNair and Aden Flint as Boro’s new signings though it’s not clear if he’ll travel to Millwall for Saturday’s opening game of the season.